Footwear with fluid-filled bladder and a reinforcing structure

ABSTRACT

A sole component and a method of manufacturing the sole component are disclosed. In general, the sole component includes a fluid-filled bladder and a reinforcing structure extending around the bladder. The reinforcing structure is bonded to the exterior of the bladder, and may be recessed into the bladder. In some embodiments, the reinforcing structure extends along the side surfaces of the bladder and between upper and lower surfaces of bladder. In manufacturing the sole component, the reinforcing structure may be located within a mold, and the polymer material forming the bladder may be bonded to the reinforcing structure during the molding process.

CROSS-REFERENCE TO RELATED APPLICATION

This non-provisional U.S. Patent Application is a continuation-in-partapplication of and claims priority to non-provisional U.S. patentapplication Ser. No. 10/767,211, which was filed in the U.S. Patent andTrademark Office on Jan. 28, 2004 and entitled Article Of FootwearHaving A Fluid-Filled Bladder With A Reinforcing Structure, suchnon-provisional U.S. patent application being entirely incorporatedherein by reference. The non-provisional U.S. patent application Ser.No. 10/767,211 claims priority to provisional U.S. Patent ApplicationSer. No. 60/531,674, which was filed in the U.S. Patent and TrademarkOffice on Dec. 23, 2003 and entitled Article Of Footwear Having AFluid-Filled Bladder With A Reinforcing Structure, such provisional U.S.Patent Application being entirely incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to footwear. The invention concerns, moreparticularly, a sole component for an article of footwear and a methodof manufacturing the sole component. Although the configuration of thesole component may vary significantly within the scope of the presentinvention, the sole component generally includes a fluid-filled bladderand an external reinforcing structure secured to the bladder.

2. Description of Background Art

A conventional article of athletic footwear includes two primaryelements, an upper and a sole structure. The upper provides a coveringfor the foot that securely receives and positions the foot with respectto the sole structure. In addition, the upper may have a configurationthat protects the foot and provides ventilation, thereby cooling thefoot and removing perspiration. The sole structure is secured to a lowersurface of the upper and is generally positioned between the foot andthe ground. In addition to attenuating ground reaction forces, the solestructure may provide traction and control foot motions, such as overpronation. Accordingly, the upper and the sole structure operatecooperatively to provide a comfortable structure that is suited for awide variety of ambulatory activities, such as walking and running.

The sole structure of athletic footwear generally exhibits a layeredconfiguration that includes a comfort-enhancing insole, a resilientmidsole formed from a polymer foam, and a ground-contacting outsole thatprovides both abrasion-resistance and traction. Suitable polymer foammaterials for the midsole include ethylvinylacetate or polyurethane thatcompress resiliently under an applied load to attenuate ground reactionforces and absorb energy. Conventional polymer foam materials areresiliently compressible, in part, due to the inclusion of a pluralityof open or closed cells that define an inner volume substantiallydisplaced by gas. That is, the polymer foam includes a plurality ofbubbles that enclose the gas. Following repeated compressions, the cellstructure may deteriorate, thereby resulting in decreasedcompressibility of the foam. Accordingly, the force attenuation andenergy absorption characteristics of the midsole may decrease over thelifespan of the footwear.

One manner of reducing the weight of a polymer foam midsole anddecreasing the effects of deterioration following repeated compressionsis disclosed in U.S. Pat. No. 4,183,156 to Rudy, hereby incorporated byreference, in which ground reaction force attenuation is provided by afluid-filled bladder formed of an elastomeric materials. The bladderincludes a plurality of tubular chambers that extend longitudinallyalong a length of the sole structure. The chambers are in fluidcommunication with each other and jointly extend across the width of thefootwear. The bladder may be encapsulated in a polymer foam material, asdisclosed in U.S. Pat. No. 4,219,945 to Rudy, hereby incorporated byreference. The combination of the bladder and the encapsulating polymerfoam material functions as a midsole. Accordingly, the upper is attachedto the upper surface of the polymer foam material and an outsole ortread member is affixed to the lower surface.

Bladders of the type discussed above are generally formed of anelastomeric material and are structured to have an upper and lowerportions that enclose one or more chambers therebetween. The chambersare pressurized above ambient pressure by inserting a nozzle or needleconnected to a fluid pressure source into a fill inlet formed in thebladder. Following pressurization of the chambers, the fill inlet issealed and the nozzle is removed.

Fluid-filled bladders suitable for footwear applications may bemanufactured by a two-film technique, in which two separate sheets ofelastomeric film are formed to exhibit the overall peripheral shape ofthe bladder. The sheets are then bonded together along their respectiveperipheries to form a sealed structure, and the sheets are also bondedtogether at predetermined interior areas to give the bladder a desiredconfiguration. That is, the interior bonds provide the bladder withchambers having a predetermined shape and size. Such bladders have alsobeen manufactured by a blow-molding technique, wherein a molten orotherwise softened elastomeric material in the shape of a tube is placedin a mold having the desired overall shape and configuration of thebladder. The mold has an opening at one location through whichpressurized air is provided. The pressurized air induces the liquefiedelastomeric material to conform to the shape of the inner surfaces ofthe mold. The elastomeric material then cools, thereby forming a bladderwith the desired shape and configuration.

SUMMARY OF THE INVENTION

The present invention is an article of footwear incorporating a solecomponent that includes a bladder and a reinforcing structure. Thebladder is formed of a barrier material, and the bladder encloses apressurized fluid that exerts an outward force upon the barriermaterial. The reinforcing structure is at least partially recessed intothe barrier material and bonded to the barrier material. At least aportion of the reinforcing structure may be placed in tension by theoutward force upon the barrier material. The reinforcing structure mayalso restrain distension or outwardly-directed swelling of the bladderdue to the outward force upon the barrier material, and the reinforcingstructure may be formed of a material with a greater modulus ofelasticity than the barrier material.

The bladder may include a first surface and an opposite second surface.The first surface may be joined to the second surface by a plurality ofinterior bonds that are spaced inward from a sidewall of the bladder. Inaddition, the bladder may include at least one flexion indentationformed in the second surface, the indentation may extend, for example,from a lateral side of the bladder to a medial side of the bladder. Asan alternative, the indentation may extend in a generally longitudinaldirection. At least one of the interior bonds may join the first surfacewith the indentation.

The reinforcing structure may include a first portion, a second portion,and a plurality of connecting portions. The first portion may bepositioned at an interface of the first surface and the sidewall, andthe first portion may extend along a lateral side of the bladder, arounda heel region of the bladder, and along a medial side of the bladder.The second portion may be spaced from the first portion and positionedat an interface of the second surface and the sidewall. In addition, thesecond portion may extend along the lateral side, around the heelregion, and along a medial side of the bladder. The connecting portionsmay extend along the sidewall and between the first portion and thesecond portion, with the connecting portions being recessed intosidewall. The connecting portions may also be inclined with respect tothe first portion and the second portion.

Another aspect of the present invention involves a method ofmanufacturing a sole component for an article of footwear. The methodincludes the steps of molding a fluid-filled bladder from a polymermaterial, recessing a reinforcing member into the bladder, and bondingthe reinforcing member to the bladder. Accordingly, the reinforcingmember may be placed within the mold prior to introducing the polymermaterial forming the bladder.

The advantages and features of novelty characterizing the presentinvention are pointed out with particularity in the appended claims. Togain an improved understanding of the advantages and features ofnovelty, however, reference may be made to the following descriptivematter and accompanying drawings that describe and illustrate variousembodiments and concepts related to the invention.

DESCRIPTION OF THE DRAWINGS

The foregoing Summary of the Invention, as well as the followingDetailed Description of the Invention, will be better understood whenread in conjunction with the accompanying drawings.

FIG. 1 is a lateral side elevational view of an article of footwearhaving a first sole component in accordance with the present invention.

FIG. 2 is a first perspective view of the first sole component.

FIG. 3 is a second perspective view of the first sole component.

FIG. 4 is a third perspective view of the first sole component.

FIG. 5 is a top plan view of the first sole component.

FIG. 6 is a bottom plan view of the first sole component.

FIG. 7 is a first side elevational view of the first sole component.

FIG. 8 is a second side elevational view of the first sole component.

FIGS. 9A-9E are cross-sectional views of the first sole component, asdefined by section lines 9A-9E in FIG. 5.

FIG. 9F is a cross-sectional view of the first sole component, asdefined by section line 9F-9F in FIG. 7.

FIG. 9G is a cross-sectional view of the article of footwear, as definedby section line 9G-9G in FIG. 1.

FIG. 10 is a first exploded perspective view of the first solecomponent.

FIG. 11 is a second exploded perspective view of the first solecomponent.

FIG. 12A is a top plan view of an upper mold portion of a mold forforming the first sole component.

FIG. 12B is a side elevational view of the upper mold portion.

FIG. 13A is a top plan view of a lower mold portion of the mold.

FIG. 13B is a side elevational view of the lower mold portion.

FIGS. 14A-14E depict various manufacturing steps in forming the firstsole component.

FIG. 15 is a perspective view of a second sole component in accordancewith the present invention.

FIG. 16 is an exploded perspective view of the second sole component.

FIG. 17 is a perspective view of a third sole component in accordancewith the present invention.

FIG. 18 is an exploded perspective view of the third sole component.

FIG. 19 is a perspective view of another embodiment of the third solecomponent.

FIG. 20 is a side elevational view of the footwear depicting yet anotherembodiment of the third sole component.

FIG. 21 is a top plan view of a fourth sole component.

FIG. 22 is a lateral side elevational view of an article of footwearhaving a fifth sole component in accordance with the present invention.

FIG. 23 is a perspective view of the fifth sole component.

FIG. 24 is a lateral side elevational view of an article of footwearhaving a sixth sole component in accordance with the present invention.

FIG. 25 is a perspective view of a seventh sole component in accordancewith the present invention.

FIG. 26 is a first side elevational view of an eighth sole component inaccordance with the present invention.

FIGS. 27A and 27B are cross-sectional views of the eighth solecomponent, as defined by section lines 27A and 27B in FIG. 26.

FIG. 28 is a cross-sectional view corresponding with FIG. 9E anddepicting another embodiment of the first sole component.

FIGS. 29A and 29B are cross-sectional views corresponding with FIG. 9Cand depicting yet another embodiment of the first sole component.

FIGS. 30A and 30B are side elevational views of a ninth sole componentin accordance with the present invention.

FIGS. 31A and 31 b are side elevational views of a tenth sole componentin accordance

FIG. 32 is a cross-sectional view through a heel region of an eleventhsole component in accordance with the present invention.

FIG. 33 is a side elevational view of a twelfth sole component inaccordance with the present invention.

FIG. 34 is a side elevational view of a thirteenth sole component inaccordance with the present invention.

FIGS. 35A and 35B are cross-sectional views of the thirteenth solecomponent, as defined by section lines 35A and 35B in FIG. 34.

FIG. 36 is a side elevational view of the thirteenth sole component incombination with an outsole.

FIGS. 37A and 37B are cross-sectional views of the thirteenth solecomponent and outsole, as defined by section lines 37A and 37B in FIG.36.

FIG. 37C is a cross-sectional view corresponding with FIG. 37B andshowing an alternate configuration.

FIG. 38 is a lateral side elevational view of an article of footwearhaving a fourteenth sole component in accordance with the presentinvention.

FIGS. 39A and 39B are side elevational views of the fourteenth solecomponent.

FIGS. 40A and 40B are schematic bottom plan views of outsoles.

DETAILED DESCRIPTION OF THE INVENTION

Introduction

The following discussion and accompanying figures disclose variousembodiments of a sole component suitable for footwear applications. Inaddition, a method of manufacturing the sole component is disclosed.Concepts related to the sole component and manufacturing method aredisclosed with reference to footwear having a configuration that issuitable for running. The sole component is not limited solely tofootwear designed for running, and may be applied to a wide range ofathletic footwear styles, including basketball shoes, cross-trainingshoes, walking shoes, tennis shoes, soccer shoes, and hiking boots, forexample. The sole component may also be applied to footwear styles thatare generally considered to be non-athletic, including dress shoes,loafers, sandals, and work boots. The concepts disclosed herein apply,therefore, to a wide variety of footwear styles.

An article of footwear 10, as depicted in FIG. 1, includes an upper 11and a sole structure 12. Upper 11 may incorporate a plurality materialelements (e.g., textiles, foam, and leather) that are stitched oradhesively bonded together to form an interior void for securely andcomfortably receiving a foot. The material elements may be selected andlocated with respect to upper 11 in order to selectively impartproperties of durability, air-permeability, wear-resistance,flexibility, and comfort, for example. In addition, upper 11 may includea lace that is utilized in a conventional manner to modify thedimensions of the interior void, thereby securing the foot within theinterior void and facilitating entry and removal of the foot from theinterior void. The lace may extend through apertures in upper 11, and atongue portion of upper 11 may extend between the interior void and thelace. Accordingly, upper 11 itself may have a substantially conventionalconfiguration within the scope of the present invention.

Sole structure 12 is secured to upper 11 and includes a midsole 13 andan outsole 14. A conventional midsole is primarily formed of a polymerfoam material, such as polyurethane or ethylvinylacetate, as discussedin the Background of the Invention section. In contrast with thestructure of a conventional midsole, midsole 13 incorporates a solecomponent 20, as depicted in FIGS. 2-11, that includes a fluid-filledbladder 30 and an external reinforcing structure 40. Sole component 20provides ground reaction force attenuation as footwear 10 impacts theground during running, walking, or other ambulatory activities. Inaddition, sole component 20 may impart stability or otherwise controlfoot motions, such as the degree of pronation. Outsole 14 is secured toa lower surface of midsole 13 and is formed of a durable, wear-resistantmaterial suitable for engaging the ground. Sole structure 12 may alsoinclude an insole 18 with the configuration of a thin cushioning member.Insole 18 may be positioned within the interior void formed by upper 11and located to contact a plantar surface of the foot, thereby enhancingthe overall comfort of footwear 10.

The following discussion references various general regions of footwear10, upper 11, and sole structure 12 based upon their relative locations.For reference purposes, footwear 10 may be divided into three generalregions: a forefoot region 15, a midfoot region 16, and a heel region17, as depicted in FIG. 1. Forefoot region 15 generally includesportions of footwear 10 corresponding with the toes and the jointsconnecting the metatarsals with the phalanges. Midfoot region 16generally includes portions of footwear 10 corresponding with the archarea of the foot, and heel region 17 corresponds with rear portions ofthe foot, including the calcaneus bone. Regions 15-17 are not intendedto demarcate precise areas of footwear 10. Rather, regions 15-17 areintended to represent general areas of footwear 10 to aid in thefollowing discussion. In addition to footwear 10, regions 15-17 may alsobe applied to upper 11, sole structure 12, and individual elementsthereof.

Sole Component Structure

Sole component 20 includes an upper surface 21 and an opposite lowersurface 22. Upper surface 21 is secured to upper 11 in a conventionalmanner, such as adhesive bonding, and may be contoured to conform withthe shape of the plantar surface of the foot. Accordingly, upper surface21 may exhibit an elevation in heel region 15 that is greater than anelevation in forefoot region 15, with midfoot region 16 forming atransition between the elevations. Differences in the overall thicknessof sole component 20 account for the elevation in heel region 15 that isgreater than the elevation in forefoot region 15. In general, thethickness of sole component 20 may range, for example, from 0.15 inchesin the forward-most portion of forefoot region 15 to approximately 0.70inches at the interface of forefoot region 15 and midfoot region 16.Similarly, the thickness of sole component 20 may range, for example,from 0.70 inches to approximately 1.20 inches in heel region 17.

The overall shape of sole component 20, as depicted in the plan view ofFIGS. 5 and 6, corresponds with the shape of a foot. Accordingly, thewidth of heel region 17 may be less than a width of forefoot region 15to accommodate the varying width dimensions of the foot. Outsole 14 isalso secured to lower surface 22 in a conventional manner, such asadhesive bonding. In addition to upper surface 21 and lower surface 22,sole component 20 includes a lateral side surface 23 and an oppositemedial side surface 24. Both side surfaces 23 and 24 are exposedportions of midsole 13 and have a tapered configuration from heel region17 to forefoot region 15 that facilitates the difference in elevationbetween heel region 17 and forefoot region 15.

The primary elements of bladder 30 are a upper barrier layer 31 and alower barrier layer 32 that are substantially impermeable to apressurized fluid contained by bladder 30. Upper barrier layer 31 andlower barrier layer 32 are bonded together around their respectiveperipheries to form a peripheral bond 33 and cooperatively form a sealedchamber, in which the pressurized fluid is located. The pressurizedfluid contained by bladder 30 induces an outward force upon barrierlayers 31 and 32 that tends to separate or otherwise press outward uponbarrier layers 31 and 32, thereby distending barrier layers 31 and 32.In order to restrict the degree of outwardly-directed swelling (i.e.,distension) of barrier layers 31 and 32 due to the outward force of thepressurized fluid, a plurality of interior bonds 34 are formed betweenbarrier layers 31 and 32. Interior bonds 34 are spaced inward from sidesurfaces 23 and 24, and interior bonds 34 are distributed throughoutsole component 20. In the absence of interior bonds 34, the outwardforce induced by the pressurized fluid would impart a rounded orotherwise bulging configuration to bladder 30, particularly in areascorresponding with upper surface 21 and lower surface 22. Interior bonds34, however, restrict the degree of the outwardly-directed swelling ordistension of barrier layers 31 and 32 and retain the intended contoursof upper surface 21 and lower surface 22.

Interior bonds 34 may exhibit a variety of configurations within thescope of the present invention. In heel region 17, the indentationsformed by interior bonds 34 have a greater depth than in forefoot region15 due to the increased overall thickness of sole component 20 in heelregion 17. In addition, the area of each interior bond 34 in heel region17 is generally greater than the area of each interior bond 34 inforefoot region 15. The position of interior bonds 34 with respect toupper surface 21 and lower surface 22 may also vary. For example,interior bonds 34 may be positioned so as to be closer to upper surface21, midway between surfaces 21 and 22, or at a position that is closerto lower surface 22.

During running or walking, sole component 20 generally flexes orotherwise bends to accommodate the natural flexing of the foot,particularly in forefoot region 15. In order to facilitate the flexingof sole component 20, a pair of flexion indentations 35 are formed inbladder 30. Each flexion indentation 35 extends laterally across a lowerportion of bladder 30. That is, flexion indentations 35 extend betweenside surfaces 23 and 24, and flexion indentations 35 are formed in lowersurface 22. The location of flexion indentations 35 is also selectedbased upon the average location of the joints between the metatarsalsand the proximal phalanges of the foot. More particularly, flexionindentations 35 are spaced such that one flexion indentation 35 islocated forward of the joints between the metatarsals and the proximalphalanges and the other flexion indentation 35 is located behind thejoints between the metatarsals and the proximal phalanges. The specificlocations of flexion indentations 35 may be selected, for example, to bethree standard deviations away from the average position of the jointsbetween the metatarsals and the proximal phalanges, as determinedthrough statistical anatomical data. Depending upon the specificconfiguration and intended use of sole component 20, however, thelocation of flexion indentations 35 may vary significantly from thepositions discussed above.

Flexion indentations 35 extend laterally (i.e., between side surfaces 23and 24) across lower surface 22. Although this configuration is suitablefor footwear structured for running and a variety of other athleticactivities, flexion indentations 35 may extend in a generallylongitudinal direction (i.e., between forefoot region 15 and heel region17) in footwear structured for athletic activities such as basketball,tennis, or cross-training. Accordingly, flexion indentations 35 mayextend in a variety of directions in order to provide a defined line offlexion in sole component 20. The figures also depict flexionindentations 35 as extending entirely across bladder 30. In someembodiments, however, flexion indentations 35 may extend only partiallyacross a portion of bladder 30.

Flexion indentations 35 define portions of sole component 20 that have areduced thickness. Given that the degree of force necessary to bend anobject is generally dependent upon the thickness of the object, thereduced thickness of sole component 20 in the areas of flexionindentations 35 facilitates flexing. In addition, portions of outsole 14may extend into flexion indentations 35, thereby forming a stiffer, lesscompressible areas of sole structure 12 that also facilitate flexingabout flexion indentations 35.

Flexion indentations 35 form an indentation in lower surface 22 thatcorresponds with the locations of various interior bonds 34. Referringto FIG. 9D, a cross-section through one of flexion indentations 35 isdepicted. With respect to this area, interior bonds 34 extend downwardto bond upper barrier layer 31 with the portion of lower barrier layer32 that defines the flexion indentation 35. Some prior art bladdersincorporate bonds that form flexion points, and the flexion points mayform relatively hard areas due to the lack of a fluid cushion in thearea of the flexion points. That is, the flexion points generally formnon-cushioning areas of the prior art bladders. In contrast with theprior art flexion points, flexion indentations 35 form a fluid-filledportion of bladder 30 in areas between the connection of interior bonds34 to flexion indentations 35. In other words, a space is formed betweenflexion indentations 35 and upper barrier layer 31 that includes thefluid such that flexion indentations 35 provide an advantage ofsimultaneously accommodating flexing and providing ground reaction forceattenuation. As an alternative, no interior bonds 34 may be formed inareas that define flexion indentations 35.

A variety of thermoplastic polymer materials may be utilized for bladder30, and particularly barrier layers 31 and 32, including polyurethane,polyester, polyester polyurethane, and polyether polyurethane. Anothersuitable material for bladder 30 is a film formed from alternatinglayers of thermoplastic polyurethane and ethylene-vinyl alcoholcopolymer, as disclosed in U.S. Pat. Nos. 5,713,141 and 5,952,065 toMitchell et al, hereby incorporated by reference. A variation upon thismaterial wherein the center layer is formed of ethylene-vinyl alcoholcopolymer; the two layers adjacent to the center layer are formed ofthermoplastic polyurethane; and the outer layers are formed of a regrindmaterial of thermoplastic polyurethane and ethylene-vinyl alcoholcopolymer may also be utilized. Bladder 30 may also be formed from aflexible microlayer membrane that includes alternating layers of a gasbarrier material and an elastomeric material, as disclosed in U.S. Pat.Nos. 6,082,025 and 6,127,026 to Bonk et al., both hereby incorporated byreference. In addition, numerous thermoplastic urethanes may beutilized, such as PELLETHANE, a product of the Dow Chemical Company;ELASTOLLAN, a product of the BASF Corporation; and ESTANE, a product ofthe B.F. Goodrich Company, all of which are either ester or ether based.Still other thermoplastic urethanes based on polyesters, polyethers,polycaprolactone, and polycarbonate macrogels may be employed, andvarious nitrogen blocking materials may also be utilized. Additionalsuitable materials are disclosed in U.S. Pat. Nos. 4,183,156 and4,219,945 to Rudy, hereby incorporated by reference. Further suitablematerials include thermoplastic films containing a crystalline material,as disclosed in U.S. Pat. Nos. 4,936,029 and 5,042,176 to Rudy, herebyincorporated by reference, and polyurethane including a polyesterpolyol, as disclosed in U.S. Pat. Nos. 6,013,340; 6,203,868; and6,321,465 to Bonk et al., also hereby incorporated by reference.

The fluid within bladder 30 may be any of the gasses disclosed in U.S.Pat. No. 4,340,626 to Rudy, hereby incorporated by reference, such ashexafluoroethane and sulfur hexafluoride, for example. The fluid mayalso include gasses such as pressurized octafluorapropane, nitrogen, orair. In addition to gasses, various gels or liquids may be sealed withinbladder 30. Accordingly, a variety of fluids are suitable for bladder30. With regard to pressure, a suitable fluid pressure is fifteen poundsper square inch, but may range from zero to thirty pounds per squareinch. Accordingly, the fluid pressure within bladder 30 may berelatively high, or the fluid pressure may be at ambient pressure or ata pressure that is slightly elevated from ambient in some embodiments ofthe invention.

Reinforcing structure 40 forms a reinforcing cage that is bonded orotherwise secured to an exterior of bladder 30. In general, reinforcingstructure 40 generally extends around portions of the periphery ofbladder 30, and portions of reinforcing structure 40 extend along sidesurfaces 23 and 24 of sole component 20. Reinforcing structure 40extends, therefore, between upper surface 21 and lower surface 22. Inaddition, the material forming reinforcing structure 40 exhibits agreater modulus of elasticity than the material forming bladder 30.Accordingly, the configuration and material properties of reinforcingstructure 40 may impart reinforcement to sole component 20.

Interior bonds 34, as discussed above, are spaced inward from sidesurfaces 23 and 24 to restrict the degree of outwardly-directed swelling(i.e., distension) of barrier layers 31 and 32, particularly in areascorresponding with upper surface 21 and lower surface 22. Interior bonds34 may not, however, significantly restrict the outwardly-directedswelling of side surfaces 23 and 24. One purpose of reinforcingstructure 40 is, therefore, to restrict the degree of outwardly-directedswelling in side surfaces 23 and 24, thereby retaining the intendedoverall shape of sole component 20.

Reinforcing structure 40 includes an upper portion 41, a lower portion42, and a plurality of connecting portions 43. Upper portion 41 exhibitsa generally U-shaped configuration and is positioned at the interface ofupper surface 21 and side surfaces 23 and 24. Accordingly, upper portion41 extends along lateral side 23 from forefoot region 15 to heel region17, extends around heel region 17, and also extends along medial side 24from forefoot region 15 to heel region 17. Lower portion 42 alsoexhibits a generally U-shaped configuration and is positioned at theinterface of lower surface 22 and side surfaces 23 and 24. Whereas upperportion 41 extends over portions of both upper surface 21 and sidesurfaces 23 and 24, lower portion 42 extends over side surfaces 23 and24. That is, lower portion 42 covers areas of side surfaces 23 and 24that are adjacent to lower surface 22, but lower portion 42 does notgenerally extend over lower surface 22. Lower portion 42 extends throughheel region 17 and may extend into midfoot region 16. As depicted in thefigures, however, lower portion 42 does not extend into forefoot region15. Connecting portions 43 extend along side surfaces 23 and 24 and alsoextend between upper portion 41 and lower portion 42. Connectingportions 43 extend in a diagonal direction between upper portion 41 andlower portion 42. More particularly, connecting portions 43 exhibit aforwardly-inclined configuration, but may also be substantially verticalor rearwardly-inclined.

Upper portion 41, lower portion 42, and connecting portions 43collectively form a plurality of apertures that expose portions ofbladder 30. The apertures extend along side surfaces 23 and 24 in atleast heel region 17, and the shape of the apertures generally dependsupon the orientations of connecting portions 43 and the configurationsof upper portion 41 and lower portion 42. The apertures formed throughreinforcing structure 40 have a variety of shapes that include, forexample, a parallelogram, oval, hexagon, triangle, circle, or variousnon-geometric shapes. The shape of the apertures may affect thecompression characteristics of reinforcing structure 40 and may beselected, therefore, to provide particular properties to reinforcingstructure 40.

Reinforcing structure 40 restricts the degree of outwardly-directedswelling in side surfaces 23 and 24, thereby retaining the intendedoverall shape of sole component 20. That is, the pressurized fluidwithin bladder 30 presses outward upon barrier layers 31 and 32, andreinforcing structure 40 restrains the distension in side surfaces 23due to the fluid. Portions of reinforcing structure 40 are, therefore,placed in tension by the pressurized fluid. Although upper portion 41and lower portion 42 may experience such tension, connecting portions43, which extend along side surfaces 23 and 24, may generally experiencegreater degrees of tension. Accordingly, connecting portions 43 areplaced in tension by the fluid pressure and operate to restrict thedegree of outwardly-directed swelling or distension in side surfaces 23and 24.

The specific configuration of reinforcing structure 40 discussed aboveis intended to provide an understanding of reinforcing structure 40according to one embodiment of the invention, and as depicted in FIGS.2-11. In further embodiments of the invention, however, theconfiguration of reinforcing structure 40 may be significantly modified.For example, upper portion 41 may be limited to heel region 17 andmidfoot region 16, upper portion 41 may extend only over portions uppersurface 21, or upper portion 41 may extend only over portions of sidesurface 23 and 24. Similarly, lower portion 42 may extend through eachof regions 15-17, or lower portion 42 may extend over portions of lowersurface 22. Connecting portions 43 may also exhibit a configuration thatextends along side surfaces 23 and 24 in midfoot region 16 and forefootregion 15, and the numbers and dimensions of connecting portions 43 mayvary significantly. Accordingly, reinforcing structure 40 may have avariety of configurations within the scope of the present invention.

Reinforcing structure 40 is recessed into bladder 30 such that anoutward-facing surface of reinforcing structure 40 is generally flushwith surfaces 21-24 of bladder 30. Referring to FIG. 9F, across-sectional view through a portion of sole component 20 is depicted.The outward-facing surface of connecting portion 43, as depicted in thecross-sectional view, is generally flush with lateral side surface 23.Accordingly, lateral side surface 23 forms a recess that receivesconnecting portion 43. That is, lateral side surface 23 curves intobladder 30 so as to form a depression in which connecting portion 43 ispositioned. In this manner, the various outward-facing surfaces ofreinforcing structure 40 are generally flush with surfaces 21-24 ofbladder 30. Forming the various outward-facing surfaces of reinforcingstructure 40 to be generally flush with surfaces 21-24 of bladder 30 hasan advantage of providing a smooth exterior configuration to solecomponent 20. In some embodiments of the invention, however, theoutward-facing surfaces of reinforcing structure 40 may be inset orrecessed into bladder 30 or may protrude outward beyond bladder 30.

The various recesses that receive reinforcing structure 40 are depictedin the exploded view of FIG. 10. More particularly, bladder 30 defines afirst recess 51, a second recess 52, and a plurality of third recesses53. First recess 51 corresponds with the location of upper portion 41and extends, therefore, around the perimeter of upper surface 21.Portions of first recess 51 also extend along side surfaces 23 and 24 atthe interface of upper surface 21 and side surfaces 23 and 24. Secondrecess 52 corresponds with the location of lower portion 42 and is,therefore, positioned adjacent to peripheral bond 33 in heel region 17and portions of midfoot region 16. In addition, the plurality of thirdrecesses 51 extend between first recess 51 and second recess 52 tocorrespond with the locations of connecting portions 43.

An injection-molding process or compression-molding process, forexample, may be utilized to form reinforcing structure 40 from a diverserange of materials. Suitable materials for reinforcing structure 40include polyester, thermoset urethane, thermoplastic urethane, variousnylon formulations, blends of these materials, or blends that includeglass fibers. In addition, reinforcing structure 40 may be formed from ahigh flex modulus polyether block amide, such as PEBAX, which ismanufactured by the Atofina Company. Polyether block amide provides avariety of characteristics that benefit the present invention, includinghigh impact resistance at low temperatures, few property variations inthe temperature range of minus 40 degrees Celsius to positive 80 degreesCelsius, resistance to degradation by a variety of chemicals, and lowhysteresis during alternative flexure. Another suitable material forreinforcing structure 40 is a polybutylene terephthalate, such asHYTREL, which is manufactured by E.I. duPont de Nemours and Company.Composite materials may also be formed by incorporating glass fibers orcarbon fibers into the polymer materials discussed above in order toenhance the strength of reinforcing structure 40.

As discussed above, the material forming reinforcing structure 40exhibits a greater modulus of elasticity than the material formingbladder 30. Whereas the material forming bladder 30 is generallyflexible, the material forming reinforcing structure 40 may exhibitsemi-rigid or rigid properties. Comparisons between bladder 30 andreinforcing structure 40 may also relate to the melting point andrecrystalization temperatures. As discussed in greater detail below,materials forming bladder 30 and reinforcing structure 40 are joinedthrough a molding process. Although the melting point andrecrystalization temperatures of bladder 30 and reinforcing structure 40may vary significantly, a difference in melting points that is less than35 degrees Celsius and a different in recrystalization temperatures thatis at least 5 degrees Celsius may be beneficial to the manufacturingprocess. In some embodiments, the ultimate tensile strength of thematerial forming bladder 30 may be less than the ultimate tensilestrength of the material forming reinforcing structure 40.

Although reinforcing structure 40 may be formed from a single material,two or more materials may be incorporated into reinforcing structure 40in some embodiments of the invention. For example, upper portion 41 maybe formed from a material that exhibits lesser stiffness than a materialforming lower portion 42 and connecting portions 43. This configurationprovides a softer material adjacent to upper 11, which may enhance thecomfort of footwear 10 and promote bonding between sole structure 12 andupper 11. Portions of reinforcing structure 40 corresponding withlateral side surface 23 may also be formed with lesser stiffness thanthe portions of reinforcing structure 40 corresponding with medial sidesurface 24. In addition, some embodiments may vary the materialsthroughout reinforcing structure 40 in order to provide specificcompression, stability, and flexibility properties to particularportions of reinforcing structure 40.

Sole component 20, as described above, provides ground reaction forceattenuation as footwear 10 impacts the ground during running, walking,or other ambulatory activities. In addition, sole component 20 mayimpart stability or otherwise control foot motions, such as the degreeof pronation. The degree of ground reaction force attenuation providedby sole component 20, and the manner in which sole component 20 controlsfoot motions, are primarily determined by the configuration of bothbladder 30 and reinforcing structure 40 and the properties of thematerials forming bladder 30 and reinforcing structure 40. Accordingly,variations in the configuration of both bladder 30 and reinforcingstructure 40, and the materials utilized therein, may be employed totune or otherwise control the ground reaction force attenuation andmotion control properties of sole structure 12. The manner in which solecomponent 20 may be configured to control the ground reaction forceattenuation and motion control properties of footwear 10 will bediscussed in greater detail in the following material.

Lower surface 22 forms an upwardly-beveled area 25 in a rear-lateralportion of sole component 20 in order to permit the footwear to smoothlyroll both forward and to the medial side following heel strike. Asdepicted in FIGS. 1, 6, and 7, the vertical thicknesses of the portionsof bladder 30 and reinforcing structure 40 forming lateral side surface23 decrease in rear portions of heel region 17. The rationale for thedecreased thickness, which forms beveled area 25, corresponds with thetypical motion of the foot during running, which proceeds as follows:Initially, the heel strikes the ground, followed by the ball of thefoot. As the heel leaves the ground, the foot rolls forward so that thetoes make contact, and finally the entire foot leaves the ground tobegin another cycle. During the time that the foot is in contact withthe ground and rolling forward, it also rolls from the outside orlateral side to the inside or medial side, a process called pronation.While the foot is air-borne and preparing for another cycle, theopposite process, called supination, occurs.

An advantage of beveled area 25 is to permit footwear 10 to smoothlytransition from the position at heel strike, wherein only therear-lateral portion of sole structure 12 is in contact with the ground,to the position where a substantial portion of outsole 14 is in contactwith the ground. That is, beveled area 25 permits footwear 10 tosmoothly roll both forward and to the medial side following heel strike.As with bladder 30, the thickness of reinforcing structure 40 is alsoreduced to form beveled area 25. Furthermore, the positions ofconnecting portions 43 are selected such that a space is formed betweentwo adjacent connecting portions 43 at the location of beveled area 25.The space between adjacent connecting portions 43 further facilitates asmooth transition from the position at heel strike by providing greatercompressibility to sole component 20 at the position of beveled area 25.

The compressibility of specific areas of sole component 20 affects theground reaction force attenuation and motion control properties of solecomponent 20. In general, forming sole component 20 such that peripheralareas (i.e., the areas adjacent to side surfaces 23 and 24) are lesscompressible than interior areas enhances the stability of solecomponent 20. One manner in which peripheral compressibility isdecreased in sole component 20 is through reinforcing structure 40. Theposition of reinforcing structure 40 around the periphery of solecomponent 20, coupled with the semi-rigid, less flexible properties ofthe material forming reinforcing structure 40, operates to decrease thecompressibility of the periphery, thereby enhancing stability.

The distribution and configurations of the various interior bonds 34also affects the compressibility and flexibility of sole component 20.In general, interior bonds 34 are spaced inward from side surfaces 23and 24, and interior bonds 34 are spaced from each other. Interior bonds34 form indentations in bladder 30. Whereas surfaces 21 and 22 aregenerally horizontal, the material forming barrier layers 31 and 32extend in a generally vertical direction to form the indentations ofinterior bonds 34. During compression of sole component 20, thevertically-extending material forming interior bonds 34 also compresses,bends, or otherwise deforms, thereby decreasing the compressibility ofsole component 20 in areas immediately adjacent to interior bonds 34.That is, the presence of an interior bond 34 decreases thecompressibility of sole component 20 in the area immediately adjacent tothe interior bond 34.

Pronation, which is the rolling of the foot from the outside or lateralside to the inside or medial side, is a natural motion of the footduring running. Some individuals, however, pronate to a degree that isgenerally considered to be undesirable and sole component 20 may beconfigured, therefore, to limit the degree of pronation. As discussedabove, interior bonds 34 decrease the compressibility of sole component20 in specific areas. By positioning a greater number, for example, ofinterior bonds 34 on the medial side of sole component 20, thecompressibility of the medial side may be decreased. As the foot rollsfrom the lateral side to the medial side, the increased compressibilitymay operate to limit the degree of pronation in the foot. Accordingly,the distribution of interior bonds 34 may be selected to control footmotions, such as pronation.

The ground reaction force attenuation and motion control properties ofsole component 20 may also be affected by the configuration ofreinforcing structure 40. The dimensions of upper portion 41, lowerportion 42, and connecting portions 43 may be selected to providespecific degrees of flexibility and compressibility to portions ofreinforcing structure 40. For example, the compressibility of peripheralareas of sole component 20 may be selected through modifications in theoverall thickness of upper portion 41. Similarly, the compressibility ofheel region 17 may be selected through modifications in the dimensionsor number of connecting portions 43. The thickness of reinforcingstructure 40 may also be tapered between upper portion 41 and lowerportion 42 in order to control the compressibility of reinforcingstructure 40 or limit the degree to which reinforcing structure creasesor buckles during compression. In addition, a central area of connectingportions 43 may be thicker than upper or lower portions in order toimpart a specific compressibility, for example. In some embodiments ofthe invention, reinforcing structure 40 may be formed from two or morematerials. As discussed above, structuring sole component 20 to exhibitlesser medial compressibility may reduce the degree of pronation in thefoot. Accordingly, the material selected for a lateral side ofreinforcing structure 40 may have a lesser modulus of elasticity thanthe material selected for a medial side of reinforcing structure 40,thereby decreasing the compressibility of the medial side.

Manufacturing Process

One suitable manufacturing process for sole component 20 utilizes a mold100, as depicted in FIGS. 12A-13B. Mold 100 includes an upper moldportion 110 and a corresponding lower mold portion 120. When joinedtogether, mold portions 110 and 120 form a cavity having dimensionssubstantially equal to the exterior dimensions of sole component 20.Mold 100 may be utilized for thermoforming bladder 30 and simultaneouslybonding or otherwise securing reinforcing structure 40 to the exteriorof bladder 30. In general, reinforcing structure 40 is placed withinupper mold portion 110 and two thermoplastic polymer sheets are placedbetween mold portions 110 and 120. The thermoplastic sheets are thendrawn into the contours of mold 100 such that at least one of thethermoplastic sheets contacts and is bonded to reinforcing structure 40.In addition, mold portions 110 and 120 compress the thermoplastic sheetstogether to form peripheral bond 33. Once the thermoplastic sheets haveconformed to the shape of bladder 30, reinforcing structure 40 is bondedto the thermoplastic sheets, peripheral bond 33 is formed, and bladder30 may be pressurized with a fluid and sealed, thereby forming solecomponent 20.

Upper mold portion 110 is depicted individually in FIGS. 12A and 12B andincludes a cavity 111 that forms the portions of sole component 20corresponding with upper surface 21 and side surfaces 23 and 24. A ridge112 extends around cavity 111 and is partially responsible for formingperipheral bond 33. In addition, a plurality of protrusions 113 extendfrom a surface of cavity 111 and are partially responsible for forminginterior bonds 34. Accordingly, the area of upper mold portion 110located within the area bounded by ridge 112 forms upper surface 21 andside surfaces 23 and 24. An extension of ridge 112 extends outward fromcavity 111 and forms an L-shaped channel 114. As discussed in greaterdetail below, channel 114 is utilized to form a conduit through which afluid may be injected into sole component 20. Another feature of uppermold portion 110 is a plurality of slot vents 115 distributed throughoutcavity 111. Vents 115 provide outlets for air as a thermoplastic sheetof polymer material is drawn into the contours of upper mold portion 110during the formation of sole component 20.

Lower mold portion 120 is depicted individually in FIGS. 13A and 13B andincludes a surface 121 that forms the portion of sole component 20corresponding with lower surface 22. A ridge 122 extends around surface121 and, in combination with ridge 112, is responsible for formingperipheral bond 33. In addition, a plurality of protrusions 123 extendfrom surface 121 and join with protrusions 113 to form interior bonds34. Accordingly, the area of lower mold portion 120 located within thearea bounded by ridge 122 forms lower surface 22. An extension of ridge122 extends outward from surface 121 and forms an L-shaped channel 124.Channel 124 joins with channel 114 to form the conduit through which thefluid may be injected into sole component 20. Another feature of lowermold portion 120 is a plurality of slot vents 125 distributed throughoutsurface 121. Vents 125 provide outlets for air as a thermoplastic sheetof polymer material is drawn into the contours of lower mold portion 120during the formation of sole component 20.

The manner in which mold 100 is utilized to form sole component 20 fromreinforcing structure 40 and barrier layers 31 and 32 will now bediscussed. An injection-molding process, for example, may be utilized toform reinforcing structure 40 from the materials discussed above.Reinforcing structure 40 is then cleansed with a detergent or alcohol,for example, in order to remove surface impurities, such as a moldrelease agent or fingerprints. The surface of reinforcing structure 40may also be plasma treated to enhance bonding with bladder 30.

Following formation and cleansing, reinforcing structure 40 is placedbetween mold portions 110 and 120 and then positioned within upper moldportion 110, as depicted in FIGS. 14A and 14B, respectively. Asdiscussed in the above material, upper mold portion 110 forms theportions of sole component 20 corresponding with upper surface 21 andside surfaces 23 and 24. In the embodiment of sole component 20discussed above, reinforcing structure 40 is generally bonded to uppersurface 21 and side surfaces 23 and 24. Accordingly, positioningreinforcing structure 40 within upper mold portion 110, as depicted inFIG. 14B, properly positions reinforcing structure 40 with respect tomold 100 for the process of forming sole component 20. A variety oftechniques may be utilized to secure reinforcing structure 40 withinupper mold portion 110, including a vacuum system, various seals, ornon-permanent adhesive elements, for example. In addition, reinforcingstructure 40 may include various tabs that define apertures, and uppermold portion 110 may include protrusion that engage the apertures tosecure reinforcing structure 40 within upper mold portion 110.

A plurality of conduits may extend through mold 100 in order to channela heated liquid, such as water, through mold 100. The heated liquidraises the overall temperature of mold 100 to approximately 180 degreesFahrenheit. As noted above, reinforcing structure 40 is positionedwithin mold 100, and reinforcing structure 40 conducts the heat frommold 100, thereby raising the temperature of reinforcing structure 40 toapproximately 180 degrees Fahrenheit. In some embodiments of theinvention, reinforcing structure 40 may be heated prior to placementwithin mold 100 in order to decrease manufacturing times.

Following placement of reinforcing structure 40 within upper moldportion 110, a pair of thermoplastic polymer sheets that form barrierlayers 31 and 32 are heated and then positioned between mold portions110 and 120, as depicted in FIG. 14C. The temperature to which barrierlayers 31 and 32 are heated depends upon the specific material used. Asnoted above, barrier layers 31 and 32 may be formed from a variety ofmaterials, including alternating layers of thermoplastic polyurethaneand ethylene-vinyl alcohol copolymer, which has a melting temperaturebetween 350 and 360 degrees Fahrenheit. The temperature to which thesurfaces of barrier layers 31 and 32 may be heated is between 400 and450 degrees Fahrenheit, which generally melts the surface of barrierlayers 31 and 32 without melting the interior.

The thickness of upper barrier layer 31 prior to molding may be greaterthan the thickness of lower barrier layer 32. Although barrier layers 31and 32 may exhibit different thicknesses prior to molding, each ofbarrier layers 31 and 32 may have a substantially uniform thicknessprior to molding. A suitable thickness range for upper barrier layer 31prior to molding is 0.045 to 0.090 inches, with one preferred thicknessbeing 0.075 inches, and a suitable thickness range for lower barrierlayer 32 prior to molding is 0.045 to 0.065 inches, with one preferredthickness being 0.055 inches. Whereas lower barrier layer 32 only formslower surface 22, upper barrier layer 31 forms both upper surface 21 andside surfaces 23 and 24. The rationale for the difference in thicknessis that upper barrier layer 31 may stretch to a greater degree in orderto form both upper surface 21 and side surfaces 23 and 24. Accordingly,differences between the original, pre-stretched thicknesses of barrierlayers 31 and 32 compensate for thinning in upper barrier layer 31 thatmay occur when upper barrier layer 31 is stretched or otherwisedistorted during the formation of upper surface 21 and side surfaces 23and 24.

Once barrier layers 31 and 32 are positioned, mold portions 110 and 120are then located such that ridge 112 aligns with ridge 122 and thevarious protrusions 113 are aligned with protrusions 123. In thisposition, the areas of mold portions 110 and 120 that form correspondingportions of sole component 20 are positioned on opposite sides ofbarrier layers 31 and 32 and are also aligned. Mold portions 110 and 120then translate toward each other such that mold 100 contacts andcompresses barrier layers 31 and 32, as depicted in FIG. 14D.

As mold 100 contacts and compresses portions of barrier layers 31 and32, a fluid, such as air, having a positive pressure in comparison withambient air may be injected between barrier layers 31 and 32 to inducebarrier layers 31 and 32 to respectively contact and conform to thecontours of mold portions 110 and 120. A variety of methods may beemployed to pressurize the area between barrier layers 31 and 32. Forexample, the fluid may be directed through the conduit formed bychannels 114 and 124. That is, a needle may placed between barrierlayers 31 and 32 and between channels 114 and 124 to deliver a fluidthat travels down the conduit and into the area forming sole component20. Air may also be removed from the area between barrier layers 31 and32 and mold portions 110 and 120 through vents 115 and 125, therebydrawing barrier layers 31 and 32 onto the surfaces of mold portions 110and 120. That is, at least a partial vacuum may be formed between thebarrier layers 31 and 32 and the surfaces of mold portions 110 and 120.In addition, drawing barrier layers 31 and 32 onto the surfaces of moldportions 110 and 120 also draws barrier layers 31 and 32 into contactwith reinforcing structure 40. Accordingly, barrier layers 31 and 32contact and are bonded to reinforcing structure 40 during this portionof the manufacturing process.

As the area between barrier layers 31 and 32 is pressurized and air isremoved from the area between barrier layers 31 and 32 and from betweenmold portions 110 and 120, barrier layers 31 and 32 conform to the shapeof mold 100 and are bonded together. More specifically, barrier layers31 and 32 stretch, bend, or otherwise conform to extend along thesurfaces of cavity 111 and surface 121 and form the general shape ofbladder 30. Ridge 112 and ridge 122 also compress a linear area ofbarrier layers 31 and 32 to form peripheral bond 33. In addition,barrier layers 31 and 32 conform to the shapes of protrusions 113 and123 and are bonded together by being compressed between protrusions 113and 123, thereby forming interior bonds 34.

Although barrier layers 31 and 32 conform to extend along the surfacesof cavity 111 and surface 121, upper barrier layer 31 generally does notcontact the portions of cavity 111 that are covered by reinforcingstructure 40. Rather, upper barrier layer 31 contacts and is compressedagainst the inward-facing surface of reinforcing structure 40, therebybonding upper barrier layer 31 to reinforcing structure 40. Referring toFIG. 9F, the outward-facing surface of connecting portion 43 isgenerally flush with lateral side surface 23, and lateral side surface23 forms a recess that receives connecting portion 43. That is, lateralside surface 23 curves into bladder 20 so as to form a depression inwhich connecting portion 43 is positioned. This configuration resultsfrom the manner in which reinforcing structure 40 is placed within uppermold portion 110 and upper barrier layer 31 is compressed against theinward-facing surface of reinforcing structure 40 and bonded toreinforcing structure 40.

The various outward-facing surfaces of reinforcing structure 40 aregenerally flush with surfaces 21-24 of bladder 30. As air pressurizesthe area between barrier layers 31 and 32 and air is drawn out of mold100 through vents 115 and 125, both upper barrier layer 31 andreinforcing structure 40 are compressed against the surface of cavity111. Upper barrier layer 31 contacts the inward-facing surface ofreinforcing structure 40, conforms to the shape of reinforcing structure40, extends around reinforcing structure 40, and contacts the surface ofcavity 111. In this manner, the surfaces of reinforcing structure 40 areformed to be generally flush with surfaces 21-24 of bladder 30.

As barrier layers 31 and 32 conform to the shape of mold 100 and arebonded together, upper barrier layer 31 bends at the location of upperportion 41 to form side surfaces 23 and 24. Accordingly, upper barrierlayer 31 extends in a generally horizontal direction to form uppersurface 21, and upper barrier layer 31 bends at the location of upperportion 41 to extend in a generally vertical direction and form sidesurfaces 23 and 24. Accordingly, upper barrier layer 31 bends during theprocess of molding bladder 30 in order to form upper surface 21 and sidesurfaces 23 and 24.

The edges of reinforcing structure 40 exhibit a beveled configuration,as depicted in FIG. 9F, in order to facilitate the flush nature of theinterface between reinforcing structure 40 and bladder 30. In general,if reinforcing structure 40 were formed to have a rectangularcross-section without beveling, for example, upper barrier layer 31 maybe required to stretch to a greater degree, thereby causing unduethinning of upper barrier layer 31 in areas adjacent to reinforcingstructure 40. In addition, a lack of beveling may also cause a gap orspace to form between upper barrier layer 31 and reinforcing structure40. Accordingly, reinforcing structure 40 is formed to exhibit bevelededges.

During formation of the bond between upper barrier layer 31 andreinforcing structure 40, air may become trapped between upper barrierlayer 31 and reinforcing structure 40, thereby reducing theeffectiveness of the bond. In order to facilitate the removal of airfrom between upper barrier layer 31 and reinforcing structure 40, aplurality of vent apertures 44 may be formed through selected locationsof reinforcing structure 40, and may be formed through the area of upperportion 41 that corresponds with upper surface 21 in order to limit thevisibility of vent apertures 44. Vent apertures provide outlets for airand may correspond in position with the various vents 115 in upper moldportion 110.

Once sole component 20 is formed within mold 100, mold portions 110 and120 separate such that reinforcing structure 40 and barrier layers 31and 32 may be removed from mold 100, as depicted in FIG. 14E. Thepolymer materials forming reinforcing structure 40 and barrier layers 31and 32 are then permitted to cool, and a pressurized fluid may beinjected through the conduit formed by channels 114 and 124. The conduitis then sealed to enclose the fluid within bladder 30. In addition,excess portions of barrier layers 31 and 32 may be trimmed or otherwiseremoved from sole component 20. The excess portions may them be recycledor reutilized to form additional thermoplastic sheets.

Connecting portions 43 are placed in tension by the pressurized fluidand operate to restrict the degree of outwardly-directed swelling (i.e.,distension) in side surfaces 23 and 24. Prior to pressurization,reinforcing structure 40 and bladder 30 are generally in a non-tensionedstate. The pressurized fluid, however, exerts an outward force uponbladder 30, thereby placing barrier layers 31 and 32 in tension. In theabsence of reinforcing structure 40, the degree of outwardly-directedswelling of barrier layers 31 and 32 may induce a rounded or otherwisebulging configuration in side surfaces 23 and 24. Reinforcing member 40,and particularly connecting portions 43, restrain the outwardly-directedswelling due to the outward force of the pressurized fluid. Accordingly,tension is induced in connecting portions 43 through the pressurizationof bladder 30.

The distribution and configurations of the various interior bonds 34, asdiscussed above, has an effect upon the compressibility of solecomponent 20. Modifications relating to the distribution andconfigurations of interior bonds 34, which are determined by thepositions of protrusions 113 and 123 may be utilized to control variousfoot motions, such as pronation. Accordingly, foot motions may becontrolled through modifications of mold portions 110 and 120. Footwear10 may also be configured for use during different activities, such asrunning, basketball, and football, through modifications in the overallthickness of sole component 20, the distribution and configurations ofthe various interior bonds 34, and the configuration of reinforcingstructure 40. Whereas a greater overall thickness of sole component 20is suitable for running activities in order to provide greater groundreaction force attenuation, for example, a lesser overall thickness maybe more appropriate for basketball and football in order to enhancestability. Controlling pronation may also be an issue with runningactivities, and protrusions 113 and 123 may be distributed andconfigured to control pronation when footwear 10 is intended forrunning. In contrast, the degree to which pronation is controlledthrough the distribution and configuration of protrusion 113 and 123 maybe lessened when footwear 10 is intended for basketball or football.Accordingly, variations in the dimensions and configuration of solecomponent 20 may be utilized to tailor footwear 10 to specific athleticactivities.

Interior bonds 34 may also be configured to affect other properties ofsole component 20, such as stability. In some embodiments of theinvention, selected interior bonds 34 may have an elongatedconfiguration. Referring to the figures, an elongated interior bond 34is positioned at the interface of midfoot region 16 and heel region 17and extends in a medial-lateral direction. Another elongated interiorbond 34 is positioned in heel region 17. Additional elongated interiorbonds 34 are positioned in forefoot region 15 and may be orientedlongitudinally or in the medial-lateral direction. In forward portionsof forefoot region 15, for example, the elongate interior bonds 34extend longitudinally. In comparison with round, triangular, orotherwise non-elongated interior bonds 34, the elongated interior bond34 may exhibit increased resistance to shear forces, thereby enhancingthe medial to lateral stability of sole component 20. Accordingly, theformation of elongated interior bonds 34 may be one manner of enhancingthe overall stability of footwear 10.

The degree of elongation in the various interior bonds 34 also has aneffect upon the compressibility of sole component 20 in the area ofinterior bonds 34. In general, circular interior bonds 34 exhibitgreater compressibility than elongate interior bonds 34. With respect toforefoot region 15, many of the interior bonds 34 positioned betweenflexion indentations 35 exhibit a circular configuration in order toenhance the compressibility of this area. In forward portions offorefoot region 15, however, many of the interior bonds 34 exhibit anelongate configuration that decreases the compressibility of this area.

Various characteristics relating to the configuration of interior bonds34 affects the overall configuration of sole component 20. In general,the spacing of interior bonds 34 in the medial to lateral direction isapproximately 0.86 inches, but may be in a range of 0.5 to 0.6 inches inforward portions of forefoot region 15. The spacing of interior bonds 34in the longitudinal direction is approximately 0.98 inches through heelregion 17 and portions of midfoot region 16, but may be in a range of0.4 to 0.9 inches in forefoot region 17. The radius formed in thetransitions between surfaces 21 and 22 and the material extending inwardto form interior bonds 34 has an effect upon the compressibility ofinterior bonds 34 and is generally selected to be in a range of 0.125and 0.150 inches. In forward portions of forefoot region 15, however,the radius may be 0.1 inches.

Following the formation of sole component 20, upper 11 may be secured toupper surface 21 and outsole 14 may be secured to lower surface 22,thereby substantially completing the manufacture of footwear 10. Thesurface characteristics of sole component 20 may be adjusted to promotebonding between sole component 20 and other components of footwear 10.In general, the strength of an adhesive bond between lower surface 22and outsole 14, for example, may be strengthened by forming lowersurface 22 to have a relatively rough texture. Whereas an adhesive maynot effectively adhere to an entirely smooth surface, the texture of arough surface provides enhanced adhesive bonding. Although imparting arelatively rough texture to surfaces 21 and 22 may enhance bonding, adetriment to the relatively rough texture is decreased visibilitythrough the polymer material forming bladder 30. Accordingly, arelatively smooth texture may be imparted to side surfaces 23 and 24 toenhance the visibility of those portions of sole component 20 that arevisible when incorporated into footwear 10. The surface characteristicsof sole component 20 are generally determined by the surfacecharacteristics of mold 100. The portions of cavity 111 and surface 121that form upper surface 21 and lower surface 22 may, therefore, be lesssmooth than portions of cavity 111 that form side surfaces 23 and 24.Texturing surfaces of sole component 20 may also enhance bonding betweenbladder 30 and reinforcing structure 40. In some embodiments of theinvention, the inward-facing surface of reinforcing structure 40 and theportions of upper barrier layer 31 that contact reinforcing structure 40may be textured prior to bonding.

The process of bonding outsole 14 to lower surface 22 may be performedfollowing the formation of sole component 20, as discussed above.Alternately, one or more traction elements may be located within mold100 in order to form a bond between the traction elements and lowersurface 22 during the thermoforming process. That is, the tractionelements may be bonded to bladder 30 through a process that is similarto the process of bonding reinforcing structure 40 to bladder 30. Thetraction elements may be one or more elements of rubber material, forexample, that are similar in configuration to a conventional outsole.The traction elements may also be additional elements of thermoplasticmaterial that reinforce those areas of sole component 20 that contactthe ground. Accordingly, the traction elements may have a variety ofconfigurations within the scope of the present invention.

Upper portion 41 of reinforcing structure 40 extends along both themedial and lateral sides of sole component 40 and provides a definedlasting line for securing upper 11 to sole component 20, as depicted inFIG. 9G. One issue with some sole structures is that the precise extentto which the upper should be secured to the sole structure is notevident from the configuration of the sole structure. Referring to thecross-sections of FIGS. 9A-9E and 9G, reinforcing structure 40 forms aridge 45 on both the medial and lateral sides of sole component 20.Ridge 45 is an identifiable line that defines a lasting surface, therebydefining the portions of sole component 20 to which upper 11 should besecured. More particularly, upper 11 should be secured to the pastingsurface, which is the portions of upper surface 21 that are positionedinward of ridge 45. Accordingly, an adhesive, for example, may be placedbetween the portions of ridge 45 that are located on the medial andlateral sides in order to properly secure upper 11 to the lastingsurface of sole component 20.

The manner in which mold 100 is structured affects the resultingproperties of sole component 20. For example, the configurations of moldportions 110 and 120 have an effect upon the degree of stretch that mayoccur in barrier layers 31 and 32. As discussed above, the thicknessesof barrier layers 31 and 32 may be selected to account for stretchingduring the molding process. In addition, however, mold portions 110 and120 may be configured with draft angles that limit the degree ofstretching in barrier layers 31 and 32, thereby controlling theresulting thickness of barrier layers 31 and 32. For example, the draftangles of the various protrusions 113 and 123 may range from 5 to 8degrees and may extend upward to 13 degrees in heel region 17.

The configurations of mold portions 110 and 120 also affect theplacement of peripheral bond 33. One advantage of placing peripheralbond 33 at the interface of lower surface 22 and side surfaces 23 and 24is that unobstructed visibility is retained through side surfaces 23 and24. This configuration requires that upper barrier layer 31 stretch to agreater degree than lower barrier layer 32 in order to also form sidesurfaces 23 and 24. In further embodiments of the invention, however,peripheral bond 33 may be positioned at a midpoint of side surface 23and 24, or peripheral bond 33 may be positioned at the interface ofupper surface 21 and side surfaces 23 and 24. Accordingly, the elevationof peripheral bond 33 may be selected to limit or otherwise control thedegree of stretch in barrier layers 31 and 32.

The relative elevations of interior bonds 34 also affect the degree ofstretching that occurs in barrier layers 31 and 32. If, for example,interior bonds 34 are located closer to lower surface 22 than uppersurface 21, then upper barrier layer 31 must stretch downward to formthe indentations associated with interior bonds 34. Similarly, locatinginterior bonds 34 closer to upper surface 21 causes lower barrier layer32 to stretch upward to form the indentations associated with interiorbonds 34. When determining the configuration of mold 100, the degree ofstretch in barrier layers 31 and 32 may be calculated, and the relativeheights of protrusions 113 and 123 may be selected to either increase ordecrease the degree of stretch that occurs in areas of barrier layers 31and 32. Accordingly, the various interior bonds may each be formed atdifferent elevations in order to control stretch in barrier layers 31and 32.

The relative heights of the various interior bonds 34 also affects thecompressibility of sole component 20. In general, the thicknesses ofbarrier layers 31 and 32 is proportional to the stiffness of barrierlayers 31 and 32. By forming interior bonds 34 adjacent to lower surface22, upper barrier layer 31 is drawn downward and stretched. Thestretching lessens the thickness of upper barrier layer 31 and decreasesthe stiffness of upper barrier layer 31, thereby increasingcompressibility. By forming interior bonds 34 adjacent to upper surface21, however, upper barrier layer 31 is stretched to a lesser degree,thereby increasing the thickness of upper barrier layer 31 anddecreasing compressibility.

As barrier layers 31 and 32 stretch during the thermoforming process,the thickness of barrier layers 31 and 32 decreases. The desiredresulting thickness of barrier layers 31 and 32 generally depends uponthe specific use and configuration of footwear 10. Selecting theposition of peripheral bond 33, the locations of interior bonds 34, andthe initial thicknesses of barrier layers 31 and 32 provides controlover the degree of stretch in barrier layers 31 and 32. Accordingly, theposition of peripheral bond 33, the locations of interior bonds 34, andthe initial thicknesses of barrier layers 31 and 32 may be selected inorder to optimize the overall thickness of bladder 30 in each area ofsole component 20.

Controlling the degree of stretch in barrier layers 31 and 32 may alsobe utilized to provide reinforcement to portions of bladder 30. Ingeneral, areas of bladder 30 that have a greater thickness will be moredurable than areas with a lesser thickness. The differences in themodulus of elasticity between the material forming bladder 30 and thematerial forming reinforcing structure 40 may cause wear at theinterfaces between bladder 30 and reinforcing structure 40. Accordingly,the degree of stretch in barrier layers 31 and 32 may be controlled toincrease the thickness of bladder 30 in areas adjacent to reinforcingstructure 40. As discussed above, the degree of stretch in barrierlayers 31 and 32 may be controlled through a variety of mechanisms,including the configuration of mold 100, the relative thicknesses ofbarrier layers 31 and 32, and the positions for forming interior bonds34, for example.

The degree of outwardly-directed swelling (i.e., distension) of barrierlayers 31 and 32 due to the outward force of the pressurized fluid isrestricted by interior bonds 34. Despite the presence of interior bonds34, the portions of barrier layers 31 and 32 forming upper surface 21and lower surface 22 may bow outward upon pressurization with the fluidsealed within bladder 30. The outward bowing effectively bends areas ofbarrier layers 31 and 32 and may induce additional stresses in thethermoplastic polymer material forming bladder 30. One manner ofreducing the additional stresses in the thermoplastic polymer materialforming bladder 30 is to mold or otherwise form barrier layers 31 and 32to include curved surfaces corresponding with the distension that wouldoccur as a result of pressurization.

Although thermoforming is a suitable manner of forming sole component20, a blow-molding process may also be utilized. In general, a suitableblow-molding process involves positioning reinforcing structure 40within at least one of two mold portions and then positioning a parisonbetween the mold portions, such as mold portions 110 and 120. Theparison is a generally hollow and tubular structure of molten polymermaterial. In forming the parison, the molten polymer material isextruded from a die. The wall thickness of the parison may besubstantially constant, or may vary around the perimeter of the parison.Accordingly, a cross-sectional view of the parison may exhibit areas ofdiffering wall thickness. Suitable materials for the parison include thematerials discussed above with respect to bladder 30. Followingplacement of the parison between the mold portions, the mold portionsclose upon the parison and pressurized air within the parison inducesthe liquefied elastomeric material to contact the surfaces of the mold.In addition, closing of the mold portions and the introduction ofpressurized air induces the liquefied elastomeric material to contactthe surfaces of reinforcing structure 40. Air may also be evacuated fromthe area between the parison and the mold to further facilitate moldingand bonding. Accordingly, sole component 20 may also be formed through ablow molding process wherein reinforcing structure 40 is placed withinthe mold prior to the introduction of the molten polymer material.

A variety of other manufacturing techniques may also be utilized to formsole component 20, in addition to thermoforming and blow-molding. Forexample, bladder 30 may be formed separate from reinforcing structure40, and both components may be subsequently bonded together. Adual-injection technique may also be utilized to simultaneously formbladder 30 and reinforcing structure 40 from separate materials. In someembodiments, a first element corresponding with upper surface 21 andside surfaces 23 and 24 may be formed, a second element correspondingwith lower surface 22 may be joined thereto, and a third elementcorresponding with reinforcing structure 40 may then be secured to theexterior. Accordingly, structures having the general shape and featuresof sole component 20 may be formed from a variety of processes.

Additional Sole Component Configurations

The specific configuration of sole component 20 disclosed above isintended to provide an example of a sole component within the scope ofthe present invention. Various alternate configurations, however, mayalso be utilized. Referring to FIGS. 15 and 16, sole component 20 isdepicted as having a plurality of bridges 46 that extend laterallyacross upper surface 21. More particularly, four bridges 46 extendbetween medial and lateral sides of upper portion 41 and enhance thestability of sole component 20. As depicted in the figures, bridges 46are relatively narrow structures that are formed of unitary (i.e., onepiece) construction with reinforcing structure 40 and are, therefore,secured to bladder 30. As with other portions of reinforcing structure40, bridges 46 may be recessed within indentations in bladder 30 and maybe bonded to bladder 30 during the thermoforming process. Althoughbridges 46 are depicted as being relatively narrow, the width of bridges46 may be increased significantly depending upon the desired propertiesof sole component 20, and bridges 46 may form a plate that extends overheel region 17. Furthermore, bridges 46 may extend over lower surface 22or both of surfaces 21 and 22, and bridges 46 may extend through midfootregion 16 or heel region 17. Accordingly, the specific configuration ofbridges 46 may vary significantly within the scope of the presentinvention.

In addition to bridges 46, sole component 20 may also include aplurality of extensions 47, as depicted in FIGS. 17 and 18. Extensions47 are portions of reinforcing structure 40 that extend upward from solecomponent 20. Extensions 47 may be secured to an exterior of upper 11 ormay extend between the material elements forming upper 11 in order tofurther secure sole component 20 to upper 11. One purpose of extensions47 may be to extend around the foot in heel region 17, for example, toprovide additional support for the foot. Accordingly, extensions 47 mayserve the purpose of a conventional heel counter or other stabilizingstructure. Although extensions 47 may exhibit the elongated structuredepicted in the figures, a similarly-located cup-like structure 48 thatis analogous to structure of the conventional heel counter may be formedas a part of reinforcing structure 40, as depicted in FIG. 19. In yetanother embodiment, as depicted in FIG. 20, extensions 47 may bereplaced by a plurality of lacing members 49 that are positioned toextend over the instep portion of upper 11 and form apertures forreceiving the lace. Lacing members 49 may be utilized, therefore, aspart of the lacing system that modifies the dimensions of the interiorvoid, thereby securing the foot within the interior void andfacilitating entry and removal of the foot from the interior void.

Bladder 30, as disclosed in the above material, forms a single, sealedchamber for enclosing the pressurized fluid. Referring to FIG. 21,bladder 30 is depicted as having a first chamber 36 and a second chamber37 that are separated by a bond 38. First chamber 36 extends througheach of regions 15-17, whereas second chamber 37 is limited to heelregion 17. The pressure of the fluid within second chamber 37 may beless than the pressure of the fluid within first chamber 36 such thatdifferent areas of bladder 30 exhibit differing ground reaction forceattenuation and compressibility properties. In further embodiments,bladder 30 may incorporate two or more separate sealed chamberspositioned in other portions of bladder 30. Accordingly, theconfigurations of the separate sealed chambers, as well as the pressuresof the fluid within the chambers may vary significantly within the scopeof the present invention.

The sole structures of conventional articles of athletic footweargenerally incorporates a polymer foam material, such as polyurethane orethylvinylacetate. One drawback to polymer foam relates to the conceptof compression set. As an individual utilizes an article of footwear,the sole structure is repetitively compressed. Polymer foam materialsgenerally incorporate various gas-filled cells that may collapse orotherwise deteriorate following repetitive compressions, therebymodifying the ground reaction force attenuation or stability propertiesof the sole structure. In contrast with the conventional solestructures, sole structure 12, as described above, does not incorporatea polymer foam material. In some embodiments, as described below, apolymer foam material 18 may be utilized in combination with solecomponent 20.

In the various embodiments of sole component 20 discussed above, solecomponent 20 extends through each of regions 15-17 and, therefore,extends under a substantial portion of the longitudinal length of thefoot. Referring to FIGS. 22 and 23, sole component 20 extends onlythrough heel region 17, and polymer foam material 18 forms midsole 13 inforefoot region 15 and midfoot region 16. Sole component 20 may,therefore, extend through only a portion of the longitudinal length offootwear 10. In further embodiments, sole component 20 may also belimited to a single side of sole structure 12. For example, the lateralside of sole structure 12 may incorporate sole component 20, whereas themedial side incorporates foam material 18. In yet further embodiments, aportion of bladder 30 may be replaced by foam material 18 such thatreinforcing structure 40 extends around both bladder 30 and foammaterial 18.

Sole component 20 may be directly bonded to upper 11, as depicted inFIG. 1. As an alternative, polymer foam material 18 may extend betweensole component 20 and upper 11, as depicted in FIG. 24. Accordingly, anupper surface of foam material 18 may be bonded to upper 11, and solecomponent 20 may be bonded to a lower surface of foam material 18. Foammaterial 18 is depicted as having approximately one-half the height ofsole component 20, but the relative thicknesses of foam material 18 andsole component 20 may vary significantly.

The materials selected for bladder 30 and reinforcing structure 40 mayexhibit different mechanical properties, such as the modulus ofelasticity. In addition to mechanical properties, however, the materialsselected for bladder 30 and reinforcing structure 40 may also exhibitdifferent visual properties. For example, bladder 30 may be formed of agenerally clear material, whereas reinforcing structure 40 may be formedof a generally translucent or opaque material. In addition, the colorsof bladder 30 and reinforcing structure 40 may vary. Accordingly,examples of visual properties that may vary include the clarity and/orcolors of the materials forming sole component 20.

A sole component 20′ is depicted in FIG. 25 as incorporating a bladder30′ and a reinforcing structure 40′ bonded to the exterior of bladder30′. As with sole component 20, reinforcing structure 40′ forms areinforcing cage that is bonded or otherwise secured to an exterior ofbladder 30′. In general, reinforcing structure 40′ generally extendsaround portions of the periphery of bladder 30′, and portions ofreinforcing structure 40′ extend along side surfaces of bladder 30′.Reinforcing structure 40′ extends, therefore, between upper and lowersurfaces of bladder 30′. In addition, the material forming reinforcingstructure 40′ may exhibit a greater modulus of elasticity than thematerial forming bladder 30′. Accordingly, the configuration andmaterial properties of reinforcing structure 40′ may impartreinforcement to bladder 30′.

When incorporated into an article of footwear, sole component 20′ may beencapsulated within a polymer foam material, such as polyurethane orethylvinylacetate. Accordingly, sole component 20′ may replace aconventional fluid-filled bladder within a conventional sole structureof an article of footwear. Portions of sole component 20′ may be exposedthrough apertures in the foam material so as to be visible from anexterior of the footwear, or sole component 20′ may be entirelyencapsulated by the foam material. Sole component 20′ may also have morethan one chamber with fluids of differing pressure.

Another consideration in the structure of sole component 20 relates tothe relative compressibilities of various portions of sole component 20.During walking, running, or other ambulatory activities, sole component20 is compressed between the ground and the foot, and portions of solecomponent 20 deform accordingly. One factor that affects the stabilityof footwear 10 is the degree to which lower surface 22 and side surfaces23 and 24 compresses or otherwise deform during an applied load. If, forexample, the portion of lower surface 22 adjacent to lateral sidesurface 23 compresses to a greater degree than the portion of lowersurface 22 adjacent to medial side surface 24, then the portion of solecomponent 20 supporting the lateral side of the foot may become unstableand permit the foot to roll toward the lateral side. The degree to whichsurfaces of sole component 20 compress or otherwise deform in reactionto an applied load may be limited through the addition of a supplementallayer 60, as depicted in FIGS. 26-27B. In addition, supplemental layer60 may reduce the probability that relatively sharp objects (e.g.,stones, thorns, nails) will puncture bladder 30.

Supplemental layer 60 is bonded to lower surface 22 and increases theresistance of sole component 20 to deformation, thereby increasing theoverall stability of footwear 10. As depicted in the figures,supplemental layer 60 does not extend upward and into the variouscontours associated with interior bonds 34 and flexion indentations 35,thereby permitting the portions of lower barrier layer 32 that form thecontours to compress without the additional resistance imparted bysupplemental layer 60. In some embodiments, however, supplemental layer60 may extend into the various contours associated with interior bonds34 and flexion indentations 35, or supplemental layer 60 may extend intoselected contours. As an example, supplemental layer 60 may extend intocontours proximal to medial side surface 24 in order to resist pronation(i.e., an inward roll) of the foot. Furthermore, supplemental layer 60may define various apertures in areas corresponding with interior bonds34.

Supplemental layer 60 is also depicted as extending throughout lowersurface 23. In some embodiments, however, supplemental layer 60 may bepositioned only in heel region 17 or only on portions of lower surface22 that are adjacent to medial side surface 24. Supplemental layer 60may also form an aperture that places the material of supplemental layeradjacent to edges of lower surface 22. Accordingly, the position ofsupplemental layer 60 may vary significantly.

Supplemental layer 60 may be formed from any of the materials discussedabove for barrier layers 31 and 32. When, for example, barrier layers 31and 32 are formed from a thermoplastic polyurethane material,supplemental layer 60 may also be formed from a thermoplasticpolyurethane to facilitate bonding between the layers. The thickness ofsupplemental layer 60 has an effect upon the degree to which compressionof sole component 20 is limited. In general, a greater thickness forsupplemental layer 60 imparts a greater resistance to compression, and alesser thickness imparts a lesser resistance to compression. Asdiscussed above, a suitable thickness range for lower barrier layer 32prior to molding is 0.03 to 0.10 inches, with one preferred thicknessbeing 0.055 inches. Supplemental layer 60 may also have a thickness inthis range, but may extend beyond this range depending upon the desireddegree of compression resistance.

A further configuration for sole component 20 is depicted in FIG. 28. Incontrast with the generally horizontal configuration of interior bonds34 depicted in FIGS. 9A, 9B, and 9E, FIG. 28 discloses a pair ofinterior bonds 34′ between barrier layers 31 and 32 that are inclined orotherwise sloped. As discussed above, the relative elevations ofinterior bonds 34 affect the degree of stretching that occurs in barrierlayers 31 and 32. If, for example, interior bonds 34 are located closerto lower surface 22 than upper surface 21, then upper barrier layer 31must stretch downward to form the indentations associated with interiorbonds 34. Similarly, locating interior bonds 34 closer to upper surface21 causes lower barrier layer 32 to stretch upward to form theindentations associated with interior bonds 34. The degree of stretch inportions of barrier layers 31 and 32 affects the thickness of barrierlayers 31 and 32. Accordingly, the position of interior bonds 34 has aneffect upon the thickness of barrier layers 31 and 32.

Interior bonds 34′ are inclined with respect to a plane of upper surface21 or lower surface 22. More particularly, interior bonds 34′ areoriented to form a downward incline extending away from each of sidesurfaces 23 and 24. This orientation places the higher portions ofinterior bonds 34′ adjacent to side surfaces 23 and 24, and the areas ofupper barrier layer 31 adjacent to side surfaces 23 and 24 stretch to arelatively small degree to form interior bonds 34′. That is, the stretchin upper barrier layer 31 is lessened adjacent to side surfaces 23 and24 due to the configuration of interior bonds 34′. The lessened stretchin this area provides upper barrier layer 31 with greater thickness,thereby increasing the durability and stability of upper barrier layer31 adjacent to side surfaces 23 and 24.

The orientation of interior bonds 34′ places the lower portions ofinterior bonds 34′ closer to a central area of sole component 20, andthe areas of upper barrier layer 31 adjacent to the central area stretchto a relatively large degree to form interior bonds 34′. That is, thestretch in upper barrier layer 31 is increased in the central area dueto the configuration of interior bonds 34′. The increased stretch inthis area provides upper barrier layer 31 with lesser thickness, therebyincreasing the compressibility of upper barrier layer 31 in the centralarea.

The configuration of bonds between barrier layers 31 and 32 may varyfrom the specific configuration depicted in FIG. 28. For example, allbonds between barrier layers 31 and 32 may have an inclinedconfiguration similar to interior bonds 34′. In some articles offootwear, the incline of interior bonds 34′ may be reversed such thatinterior bonds 34′ are oriented to form an upward incline extending awayfrom each of side surfaces 23 and 24. FIG. 28 depicts a cross-sectionthrough a portion of sole component 20 in forefoot region 15, butinclined bonds between barrier layers 31 and 32 may be located in anyregion of footwear 10.

Another consideration related to the manufacturing process for solecomponent 20 relates to the degree of curvature in surfaces 21-24. FIGS.13A and 13B depict lower mold portion 120 as having a generally planararea for forming lower surface 22. When sole component 20 is removedfrom mold 100 and is in the uninflated and unpressurized state, lowersurface 22 will exhibit, therefore, a generally planar configuration.Depending upon the degree to which sole component 20 is pressurized,lower surface 22 may bow outward to impart a generally convexconfiguration to lower surface 22. In order to limit the degree to whichlower surface 22 bows outward and exhibits the generally convexconfiguration, lower mold portion 120 may be formed to have a convexarea for forming lower surface 22, thereby imparting a concave shape tolower surface 22 in the unpressurized state.

With reference to FIG. 29A, sole component 20 is depicted in theuninflated configuration and lower surface 22 exhibits a generallyconcave configuration. As noted above, providing lower mold portion 120with a convex area for forming lower surface 22 will impart a concaveconfiguration to lower surface 22. Upon pressurization, however, thefluid exerts an outward force upon lower barrier layer 32 and deformslower surface 22 to a generally planar configuration, as depicted inFIG. 29B. An advantage of providing lower surface 22 with a planarconfiguration, as opposed to a convex configuration, is that the overallstability of footwear 10 may be increased.

Initially forming lower surface 22 to exhibit a concave configurationprovides an effective manner of imparting a generally planarconfiguration to lower surface 22 upon pressurization. Similar conceptsmay also be applied to upper surface 21 and side surfaces 23 and 24.That is, upper surface 21 and side surfaces 23 and 24 may also be formedto exhibit a concave configuration following molding in order to imparta generally planar configuration upon pressurization. More generally,the shape of mold 100 may be utilized to impart any configuration (i.e.,concave, planar, or convex) to surfaces 21-24 depending upon theapplication and desired configuration for sole component 20.

As discussed above, two or more materials may be incorporated intoreinforcing structure 40 in some embodiments of the invention. Withreference to FIGS. 30A and 30B, upper portion 41 is formed from a firstmaterial 61, and lower portion 42 and connecting portions 43 are formedfrom a second material 62. As an example, first material 61 may exhibitlesser stiffness than second material 62. This configuration provides asofter material adjacent to upper 11, which may enhance the comfort offootwear 10 and promote bonding between sole structure 12 and upper 11.In addition, this configuration promotes bending of sole component 20during walking, running, or other ambulatory activities. Anotherconfiguration is depicted in FIGS. 31A and 31B, in which portions ofreinforcing structure 40 in medial side surface 24 are formed of firstmaterial 61 and a remainder of reinforcing structure 40 is formed ofsecond material 62. In this configuration, portions of reinforcingstructure 40 corresponding with lateral side surface 23 are formed withlesser stiffness than the portions of reinforcing structure 40corresponding with medial side surface 24 to resist pronation of thefoot. In addition, some embodiments may vary the materials throughoutreinforcing structure 40 in order to provide specific compression,stability, and flexibility properties to particular portions ofreinforcing structure 40. In addition to first material 61 and secondmaterial 62, reinforcing structure 40 may be formed from furthermaterials. As an example, first material 61 may form portions ofreinforcing structure 40 in forefoot region 15, second material 62 mayform portions of reinforcing structure 40 in midfoot region 16, and athird material may form portions of reinforcing structure 40 in heelregion 17, for example. Accordingly, the positions and numbers ofmaterials that may be incorporated into reinforcing structure 40 mayvary significantly.

Variations in the dimensions of portions of reinforcing structure 40 mayhave an effect upon the ground reaction force attenuation properties ofsole component 20, the compressibility of sole component 20, theflexibility of sole component 20, or the torsional force necessary totwist sole component 20, for example. With reference to FIG. 32, solecomponent 20 is depicted as having a configuration wherein a connectingmember 43 located in lateral side surface 23 exhibits greater thicknessthan a connecting member 43 located in medial side surface 24. Duringcourt-style athletic activities, such as tennis and basketball,providing additional support for a lateral side of the foot may preventrolling of the foot toward the lateral side during lateral cuts or othersideways movements. By increasing the thickness of connecting members 43located in lateral side surface 23, additional support may be providedfor the lateral side of the foot. As an alternative, connecting members43 located in medial side surface 24 may exhibit increased thickness tolimit pronation of the foot during running. Accordingly, variations inthe thickness of selected connecting members 43 may be utilized tocontrol motions of the foot or affect other properties of sole component20.

An increase in the width of various connecting members 43 may alsoaffect the ground reaction force attenuation properties,compressibility, and flexibility of sole component 20. With reference toFIG. 33, sole component 20 is depicted in a configuration whereinconnecting members 43 exhibit an increased width in comparison with FIG.8, for example. By increasing the width of connecting members 43 locatedin lateral side surface 23, additional support may be provided for thelateral side of the foot. As an alternative, connecting members 43located in medial side surface 24 may exhibit increased width to limitpronation of the foot during running. Accordingly, variations in thewidth of selected connecting members 43 may be utilized to controlmotions of the foot or affect other properties of sole component 20.

With reference to FIGS. 34-35B, another embodiment is depicted whereinbladder 30 includes various indented areas 63 that receive side portionsof outsole 14. Indented areas 63 may be located in any region offootwear 10, but are depicted as being located at an interface ofregions 15 and 16 and also throughout heel region 17. That is, indentedareas 63 are located at the lower portion of side surfaces 23 and 24.Indented areas 63 are depressions in bladder 30 that permit the sideportions of outsole 14 to wrap upward and onto one or both of sidesurfaces 23 and 24, as depicted in FIGS. 36-37B. As depicted in 36-37B,indented areas 63 ensure that outsole 14 is flush with the exteriorsurface of reinforcing structure 40 and the exterior of side surfaces 23and 24. In some athletic activities, portions of side surfaces 23 and24, rather than lower surface 22, make contact with the ground. Anadvantage of having outsole 14 wrap upward and onto one or both of sidesurfaces 23 and 24 is that outsole 14 limits sliding between the groundand side surfaces 23 and 24 when either of side surfaces 23 and 24 makecontact with the ground.

Although indented areas 63 are discussed above as ensuring that outsole14 is flush with the exterior surface of reinforcing structure 40 andthe exterior of side surfaces 23 and 24, outsole 14 may not be flush inall configurations of sole component 20. With reference to FIG. 37C,indented areas 63 are absent and outsole 14 extends outward and beyondthe exterior surface of reinforcing structure 40 and the exterior ofside surfaces 23 and 24. Accordingly, indented areas 63 may be absent insome embodiments.

In many of the embodiments discussed above, sole component 20 extendsentirely through a longitudinal length of footwear 10. The variousconcepts discussed above, however, may be applied to another solecomponent 20 that only extends through a portion of the length offootwear 10. With reference to FIG. 38, footwear 10 is depicted asincluding a sole component 20 that extends through heel region 17 and aportion of midfoot region 16. In midfoot region 16, sole component 20tapers downward to form a tapered area 64, as depicted in each of FIGS.39A and 39B, that interfaces with a foam element 65. More particularly,upper surface 21 approaches lower surface 22 to decrease a thickness ofbladder 30 in the tapered area. Foam element 65 extends above thetapered area and contacts upper surface 21. Whereas sole component 20 islocated in a rear area of footwear 10, foam element 65 extends forwardfrom sole element 20 and through forefoot region 15. In someembodiments, sole component 20 may be limited to forefoot region 15, anda foam element may extend rearward and through heel region 17.Alternately, sole component 20 may be limited to midfoot region 16 suchthat a pair of foam elements extend through each of regions 15 and 17.

As discussed above, supplemental layer 60 may be applied to control thedegree to which surfaces of sole component 20 compress or otherwisedeform in reaction to an applied load. As an alternative to supplementallayer 60 or in addition to supplemental layer 60, outsole 14 may bestructured to control the degree to which surfaces of sole component 20compress or otherwise deform. With reference to FIG. 40A, outsole 14 isdepicted as having a first area 14 a and a second area 14 b. First area14 a is primarily located in heel region 17, whereas second area 14 b islocated in each of forefoot region 15 and midfoot region 16. Incomparison with second area 14 b, first area 14 a may exhibit a stifferstructure to assist with controlling the degree to which surfaces ofsole component 20 compress or otherwise deform in reaction to an appliedload. Another configuration is depicted in FIG. 40B, wherein first area14 has a U-shaped design.

CONCLUSION

The preceding discussion disclosed various embodiments of a solecomponent and a method of manufacturing the sole component. In general,the sole component includes a fluid-filled bladder and a reinforcingstructure extending around the bladder. The reinforcing structure isbonded to the exterior of the bladder, and may be recessed into thebladder. In some embodiments, the reinforcing structure extends alongthe side surfaces of the bladder and between upper and lower surfaces ofbladder. In manufacturing the sole component, the reinforcing structuremay be located within a mold, and the polymer material forming thebladder may be bonded to the reinforcing structure during the moldingprocess.

The present invention is disclosed above and in the accompanyingdrawings with reference to a variety of embodiments. The purpose servedby the disclosure, however, is to provide an example of the variousfeatures and concepts related to the invention, not to limit the scopeof the invention. One skilled in the relevant art will recognize thatnumerous variations and modifications may be made to the embodimentsdescribed above without departing from the scope of the presentinvention, as defined by the appended claims.

1. An article of footwear having an upper and a sole structure securedto the upper, the sole structure comprising: a bladder formed from atleast a first sheet and a second sheet of a barrier material thatenclose a pressurized fluid, the bladder having at least a first surfaceand an opposite second surface; a reinforcing structure secured to anexterior of the bladder and at least partially recessed into the barriermaterial; a supplemental layer bonded to the second surface, thesupplemental layer being formed from a third sheet of the barriermaterial; and an outsole secured to at least one of the second surfaceand the supplemental layer, wherein the second surface defines variousindentations extending into an interior area of the bladder, and thesupplemental layer extends across the indentations and is absent fromthe interior area.
 2. The article of footwear recited in claim 1,wherein the first surface is positioned proximal the upper and thesecond surface faces away from the upper.
 3. The article of footwearrecited in claim 1, wherein the bladder includes a sidewall extendingbetween the first surface and the second surface.
 4. The article offootwear recited in claim 3, wherein the reinforcing structure isrecessed into the sidewall and extends at least partially between thefirst surface and the second surface.
 5. An article of footwear havingan upper and a sole structure secured to the upper, the sole structurecomprising: a bladder formed from a barrier material that encloses apressurized fluid, the bladder having at least an upper surface, anopposite lower surface, and a sidewall surface extending between theupper surface and the lower surface, and the bladder including aplurality of interior bonds spaced inward from the sidewall surface andjoining portions of the barrier material forming the upper surface andthe lower surface, each of the upper surface and the lower surfacedefining a plurality of indentations in areas corresponding with theinterior bonds; a reinforcing structure secured to an exterior of thebladder and at least partially recessed into the sidewall surface; asupplemental layer bonded to the lower surface and having aconfiguration of a sheet of polymer material, the supplemental layerextending across the indentations in the lower surface so as to beabsent from an area within the indentations; and an outsole secured toat least one of the lower surface and the supplemental layer.
 6. Thearticle of footwear recited in claim 5, wherein the supplemental layeris formed from the barrier material.
 7. The article of footwear recitedin claim 5, wherein the upper surface is positioned proximal the upperand the lower surface faces away from the upper.
 8. The article offootwear recited in claim 5, wherein the reinforcing structure extendsat least partially between the first surface and the second surface. 9.The article of footwear recited in claim 5, further including an outsolesecured to at least one of the lower surface and the supplemental layer.